Tuna's tale through museomics: millennia of evolution and adaptation between Mediterranean human coastal population and Atlantic bluefin tuna

For millennia, Mediterranean coastal communities have relied on fishing as a primary source of sustenance, with evidence of this practice dating back 40,000 years. Understanding the historical extent of human dependence on coastal resources is therefore essential for assessing long-term socio-economic development, human health, and the anthropogenic impact on the environment. Among the apex predators of the Mediterranean Sea, the Atlantic bluefin tuna (Thunnus thynnus) holds a prominent position, serving as both a keystone species and a vital resource for traditional sustenance. With few natural predators aside from humans, its exploitation was historically related to subsistence and small-scale commercial fisheries, primarily conducted by coastal and island communities using traditional methods such as tonnare. This study aims to achieve four key objectives: 1) to investigate the historical and cultural significance of tuna in the diets of Mediterranean coastal populations, 2) to assess potential differences in pollutant levels in tuna specimens from the pre-industrial and post-industrial eras, 3) to examine adaptive changes—at both genetic and epigenetic levels—in ancient and contemporary Mediterranean bluefin tuna populations, as well as among past and present communities engaged in traditional tuna fishing practices. Our study shows: significant differences in polycyclic aromatic hydrocarbons levels between ancient and modern bluefin tuna vertebrae; evidence of distinct population structures between ancient and contemporary tuna specimens; potential adaptive responses of tuna to anthropogenic pressures; potential variations in the allele frequencies of pollutant-related genes between populations that historically and traditionally consume tuna fish and those that do not. By integrating historical, genetic, and ecological perspectives, this research will provide a comprehensive understanding of the long-term interactions between Atlantic bluefin tuna and human populations in the Mediterranean area. Our findings will not only shed light on the extent of human influence on marine ecosystems but also reveal the adaptive responses of both species to environmental and anthropogenic pressures. Ultimately, this study underscores the need for sustainable fisheries management and conservation strategies, ensuring the resilience of bluefin tuna populations and the preservation of traditional coastal livelihoods against ongoing environmental change.